| 摘要 |
<p>1,264,383. Anti-offset agents in printing inks. SALVAT EDITORES S.A., and COLORES Y DERIVADOS S.A. 13 Feb., 1969 [14 Feb.. 1968], No. 7976/69. Heading C4A. [Also in Division B6] Printing inks comprise as an anti-offsetting agent a non-aqueous organic fluid medium containing at least 10% by wt. of dispersed waterswellable starch granules, the organic fluid medium being compatible with the ink. The medium may be an animal, vegetable or mineral oil, or deca- or tetrahydronaphthalene, preferably a petroleum fraction distilling between 260‹ and 320‹ C.; castor, tung, linseed, cottonseed, olive and coconut oils, gasoline, heavy naphtha, white spirit and high petroleum fractions are disclosed. The agent may also include 0À25- 2% by wt. of an acid or acid salt, e.g. citric, malic, or meso or racemic tartaric acids. The starch granules may have an average diameter, when dry, of up to 30 microns. Up to 20% by weight anti-offset agent may be used in the ink, preferably about 3% of an agent containing 60-65% starch, so as to introduce 1À8% starch particles into the ink. The ink to which the agent is added may have a viscosity of 200- 1,100 poise at 20‹ C., and may be based on an oil or a phenolic varnish.</p> |
